Piston



T. P. CHASE. l PlsToN.

APPLICATION FILED JUNE 23. 1916.

2 SHEETS-SHEET l.

T. P. CHASE.

PlsToNI` APPLICATION FILED JUNE 23, I9I6.

1,356,695. Patented Oct. 26, 1920.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

THERON P. CHASE, 0F DETROIT,

Specification of Letters Patent.

Application led June 23, 1916. Serial No. 105,340. Y

and ate of Michigam'have invented certain new and useful Improvements in'Plstons, of which the following is a specification, reference being had therein to the accompanying drawings.

In the operation of explosive engines of high speed type it is desirable to make the pistons, which are usually of the trunk type, as light as possible. The use of cast aluminum for such articles has been found unsatisfactory if the aluminum is carried into the lower or skirt portion of the piston where it is found liable to expand and cause trouble.

This invention relates to pistons for eX- plosive engines wherein the head and wrist pin bosses are cast integrally of aluminum while the skirt or remaining portion of the piston is formed of cast iron, steel or the like that is united either by being cast onto the aluminum or by being connected thereto in any suitable manner.

The invention consists in the matters hereinafter set forth, and more particularly pointed out in the appended claim.

In the drawings,

Figure 1 is a view in longitudinal section of a piston embodying features of the invention, showing one means of securing the cast head and the skirt together;

Fig. 2 is a view in detail in cross section showing a modification of the device; y

Fig. 3 is a view in longitudinal section shoiwing a further modification of the device, an

Fig. 4 is a view in detail showing another possible arrangement of parts.

As herein shown, and referring more particularly to Fig. 1, a head 1 is cast of aluminum with bearing pin vbosses 2 integrally formed thereon and grooves 3 for the reception of the usual piston expansion rings. A skirt 4 of cast iron or similar material is formed to embrace and engage on the lowerportion of the head to which it is firmly united either by casting one upon the other or by machining the parts to lit' In Fig. 2, a slight modification is shown siding at Detroit, in the county of lVa-yne wherein the head 5 with the vwrist pin bearing bosses is cast of aluminum and a skirt 6 of cast iron or the like secured thereto by screw threads and a holding pin 7.

" In Fig. 3 a cast head 8 with wrist pin bearing bosses is provided with a sheet metal skirt 9 the upper marginal portion 10 thereof'being spun into a suitable holding groove and the lower ymarginal portion 11 being enrolled as indicated.,l preferably.

In'Fig. 4 a skirt 12 and head of the piston are formed integrally of aluminum while the cast iron ring 14 is formed in a suitable receiving groove around the head,

Patented oct'. 26, 1920.

this particular annulus being at the point l where wear is most likely to occur and where binding eect is sometimes felt.

By this construction a piston is formed of a light material which is rigid enough ini the portions constructed of it to provide the necessary bearings for the wrist pins and for the piston ring while its parts which tend to expand, if made of the cast aluminum, or to wear too freely are formed of a better wearing material that is somewhat heavier.

Obviously, changes in the details of construction may be made without departing from the spirit of my invention and I do not care to limit myself to any particular form or arrangement of parts.

What I claim is:- l

A compos'ite piston for an internal combustion motor having a head and wrist pin bearlng bosses cast integrally of aluminum alloy having a relatively low specific gravity, and a tubular iron guide section into which said wrist pin bosses extend and which provides wearing surfaces for engagement with the inner walls of a motor cylinder at points above and below the wrist pin bearings in said bosses, the said guide section being formed with diametrically opposite wrist pin apertures concentric with the axis of the Wrist pin bosses and'having its upper end secured to said casting above the wrist pin bearings in said bosses.

In testimony whereof I affix my signature in presence of two witnessesr 

